1. Field of the Invention
The present invention relates to an over-drive gear device and more particularly, a high efficient over-drive gear device for use with a wind generator of a propeller-type windmill and the like, which transforms natural energy of wind force to electrical energy by increasing the number of rotations thereof as well as changing the direction of rotary force thereof.
2. Description of the Prior Art
There are two typical types of conventional wind generators in the art, which transform wind energy to electrical energy.
A first type of such conventional wind generators, as shown in FIG. 1, includes an H-type windmill disposed on the top of a steel tower for horizontally rotating and a generator disposed in the steel tower for connecting to a plurality of auxiliary gears disposed in a geared relationship with an axial gear of the windmill so as to increase the number of rotations of the generator. However, such a wind generator has a number of disadvantages such as, for example, difficulty in operating the wind generator and very low efficiency with respect to transforming wind energy into electrical energy.
A second type of such conventional wind generators, as shown in FIG. 2, includes a propeller-type windmill disposed on the top of a steel tower for vertically rotating and a generator having a coaxial rotor for delivering the generated electrical energy from the generator through a slip ring. However, while such a wind generator device has the advantage of abundant electrical energy produced therefrom, it is very expensive to construct the strongly built steel tower so as to support the heavy generator thereon and to install the slip ring facilities.